Asia Pacific Application Support Center

Shanghai, China

Asia Pacific Application Support Center

Shanghai, China
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Zhao X.S.,Peking Union Medical College | Kong W.J.,Peking Union Medical College | Wang S.,Peking Union Medical College | Wang S.,Asia Pacific Application Support Center | And 2 more authors.
World Mycotoxin Journal | Year: 2017

In this study, a reliable and fast method for the simultaneous quantitation of 11 mycotoxins in Alpinia oxyphylla was developed using ultra-performance liquid chromatography coupled with tandem mass spectrometry (UPLCMS/ MS). Three different extraction procedures (solid-liquid extraction, solid-phase extraction and modified QuEChERS) were evaluated. Solid-liquid extraction was fast and easy, and also provided the best recovery rate for all mycotoxins, compared to the other extraction procedures. Some crucial factors, including extraction solvent, time and temperature, were carefully optimised. Significant matrix effects were offset using matrix-matched calibration. Under these optimised conditions, our detection approach showed a good, linear dynamic range with correlation coefficients (R2) above 0.9958. The limit of quantification ranged from 0.1 to 20 μg/kg. Accuracy was determined in a selected matrix using blank samples spiked with the target mycotoxins at three different concentration levels. The recoveries ranged from 60% (T-2 toxin) to 111% (HT-2 toxin), with relative standard deviation <20%. The validated method was used to analyse 44 batches of A. oxyphylla purchased from different regions of China. Aflatoxin B1, zearalenone, ochratoxin A, fumonisin B1 and fumonisin B2 were detected in 4 mouldy samples.

Li Q.,Hunan Agricultural University | Liu Z.,Hunan Agricultural University | Liu Z.,Tsinghua University | Huang J.,Hunan Agricultural University | And 3 more authors.
Journal of the Science of Food and Agriculture | Year: 2013

Background: Fuzhuan brick tea is a kind of microbial fermented tea, which has received increasing attention in recent years owing to its benefits for human health. In this study, the anti-obesity and hypolipidemic effects of Fuzhuan brick tea water extracts (FTEs) were investigated. Results: FTEs consisted of 204.07 ± 3.38 mg g-1 polyphenol, 109.20 ± 1.36 mg g-1 flavonoids, and others. The FTEs significantly suppressed the increase of body weight and accumulation of adipose tissue, and reduced the level of serum triacylglycerol, total cholesterol and low-density lipoprotein (LDL) cholesterol in obese rats fed a high-fat diet. Moreover, FTEs attenuated the gene expression of sterol regulatory element binding protein-1c, fatty acid synthase and CCAAT/enhancer binding protein α, which is related to lipogenic metabolism. In contrast, the gene expressions of enzymes involved in energy expenditure and lipodieresis including hepatic peroxisome proliferator-activated receptor α, carnitine palmitoyltransferase 1a and LDL receptor gene expression were increased by FTE treatment. Conclusions: Our study demonstrates that FTEs have anti-obesity and hypolipidemic functions, suggesting that it might be effective for treatment of obesity and hyperlipemia. © 2012 Society of Chemical Industry.

Du Z.,Asia Pacific Application Support Center
Chinese Journal of Chromatography (Se Pu) | Year: 2011

A method was developed for the simultaneous determination and identification of 12 steroid hormone residues in pig tissues, including stanolone, aldosterone, boldenone, danazol, metandienone, methyltestosterone, nadrolone, norethindrone, progesterone, stanozolol, testosterone and testosterone propionate, using liquid chromatography-tandem triple-quadrupole linear ion trap mass spectrometry(LC-MS/MS). Homogenized pig tissue samples were purified with a Waters MCX solid phase extraction column after enzymatic hydrolysis by β-glucuroni-dase, then separated on a Venusil MP C 18 column (100 mm x 2. 1 mm, 3 μm) using gradient elution with the mobile phases of acetonitrile and water with 0. 1% (v/v) formic acid. A multiple reaction monitoring (MRM) as survey scan and an enhanced product ion (EPI) scan as dependent scan were performed in an information dependent acquisition (IDA) experiment. The compound identification was carried out by library search with a newly developed MS/MS library based on EPI spectra at three different collision energies in positive mode. The results showed that the limits of detection (LODs, S/N = 3) were in the range of 0. 2 - 0. 5 μg/kg for the steroid hormones; and with a good linearity (r >0. 99) ranged from 0. 5 to 100. 0 μ/L. The average recoveries (n =6/ of the 12 steroid hormones spiked in pig tissue samples at 5. 0 μ/kg ranged from 72. 0% to 98. 1% with the relative standard deviations (RSDs) between 3. 1% and 12. 5%. The method was applied for the qualitative and quantitative determination of steroid hormone residues in pig tissues with sensitive and accurate characteristics.

Du Z.,Asia Pacific Application Support Center
Chinese Journal of Chromatography (Se Pu) | Year: 2013

A new method has been developed using a hybrid triple-iadrupole linear ion trap (QTrap) mass spectrometer for the fast detection and identification of nine β-agonists, clen-buterol, salbutamol, ractopamine, ritodrine, terbutaline, isoxsuprine, tulobuterol, cimaterol and bambuterol, in one single liquid chromatograpny-tandem mass spectrometry (LC-MS/MS) analysis. The homogenized tissue samples were purified with liquid-liquid extraction after enzy-matic hydrolysis by β-glucuronidase/aryl snlfatase. After gradient elution separation on Cl8 LC column using acetonitrile and formic acid aqueous solution as the mobile phases, a multiple reaction monitoring (MRM) scan as survey scan and an enhanced product ion (EPI) scan as dependent scan were performed in an information dependent acquisition (IDA) experiment. Finally, the identification of the drugs was carried out by library search with a newly developed MS/MS library based on EPI spectra at three different collision energies in positive mode. The analytical method in the present study was well validated and good results were obtained with respect to precision, repeatability and spiked recovery. The limits of detection of residues were 0. 1-0. 2 μkg for β-agonists, and with a linear range from 0. 1 to 50. 0 μg/L. Three concentration levels of 0. 5, 1. 0 and 5. 0 μg/kg were spiked in pig tissues, and the overall recoveries were between 72. 0% and 95. 1% with the relative standard deviations (RSDs) between 3. 1% and 12. 1%. The real sample test showed that this method could be used for sensitive and accurate determination of β-agonist residues in pig tissues.

Yi X.,Chinese Academy of Sciences | Yi X.,Hainan University | Sun Y.,Chinese Academy of Sciences | Yang Q.,Chinese Academy of Sciences | And 13 more authors.
Journal of Proteomics | Year: 2014

Physiological and proteomic responses of Sesuvium portulacastrum leaves under salinity were investigated. Different from glycophytes, this halophyte had optimal growth at 200-300mM NaCl and accumulated more starch grains in chloroplasts under high salinity. Increased contents of soluble sugars, proline, and Na+ were observed upon salinity. X-ray microanalysis revealed that Na+ was mainly compartmentalized into cell vacuole. Quantitative proteomics produced 96 salt responsive proteins, and the majority was chloroplast-located proteins. Gene ontology analysis revealed that proteins involved in ion binding, proton transport, photosynthesis and ATP synthesis were overrepresented. The expressions of a Na+/H+ antiporter and several ATP synthase subunits were activated upon high salinity. ATP hydrolysis assay demonstrated that V-ATPase activity at tonoplast was dramatically increased upon NaCl whereas vacuolar H+-pyrophosphatase and plasma membrane P-ATPase activities were not increased, which indicated that sodium compartmentalization was mainly performed by enhancing V-ATPase activity rather than P-ATPase and H+-pyrophosphatase. Accumulation of soluble sugars as well as sodium compartmentalization maintained the osmotic balance between vacuole and cytoplasm, which finally established ionic homeostasis in saline cells in true halophytes. Biological significance: Physiological and proteomic analyses of S. portulacastrum leaves under different salinities were investigated. This true halophyte accumulated more soluble sugars, starch, proline and Na+ under high salinity. Differential proteomics produced 96 salt responsive proteins and the majority was involved in ion binding, proton transport, photosynthesis, and ATP synthesis. A Na+/H+ antiporter and several ATP synthase subunits were induced upon high salinity. ATP hydrolysis assay demonstrated that V-ATPase activity at tonoplast was dramatically increased whereas vacuolar H+-pyrophosphatase and plasma membrane ATPase activities were stable upon NaCl. These findings demonstrated that the increased Na+ was compartmentalized into vacuole by enhancing V-ATPase activity rather than H+-ATPase. © 2014.

Liu X.,Jilin University | Hu L.,Jilin University | Ge G.,CAS Dalian Institute of Chemical Physics | Yang B.,Jilin University | And 5 more authors.
Proteomics | Year: 2014

Cytochrome P450 (CYP) is one of the most important drug-metabolizing enzyme families, which participates in the biotransformation of many endogenous and exogenous compounds. Quantitative analysis of CYP expression levels is important when studying the efficacy of new drug molecules and assessing drug-drug interactions in drug development. At present, chemical probe-based assay is the most widely used approach for the evaluation of CYP activity although there are cross-reactions between the isoforms with high sequence homologies. Therefore, quantification of each isozyme is highly desired in regard to meeting the ever-increasing requirements for carrying out pharmacokinetics and personalized medicine in the academic, pharmaceutical, and clinical setting. Herein, an absolute quantification method was employed for the analysis of the seven isoforms CYP1A2, 2B6, 3A4, 3A5, 2C9, 2C19, and 2E1 using a proteome-derived approach in combination with stable isotope dilution assay. The average absolute amount measured from twelve human liver microsomes samples were 39.3, 4.3, 54.0, 4.6, 10.3, 3.0, and 9.3 (pmol/mg protein) for 1A2, 2B6, 3A4, 3A5, 2C9, 2C19, and 2E1, respectively. Importantly, the expression level of CYP3A4 showed high correlation (r = 0.943, p < 0.0001) with the functional activity, which was measured using bufalin-a highly selective chemical probe we have developed. The combination of MRM identification and analysis of the functional activity, as in the case of CYP3A4, provides a protocol which can be extended to other functional enzyme studies with wide application in pharmaceutical research. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Wu X.,Xiamen University | Tian L.,Xiamen University | Li J.,Xiamen University | Zhang Y.,Xiamen University | And 10 more authors.
Molecular and Cellular Proteomics | Year: 2012

Receptor interacting protein 3 (RIP3) is a protein kinase that plays a key role in programmed necrosis. Despite the importance of RIP3-dependent necrosis in many pathological processes, current knowledge on the function of RIP3 is very limited. Here we present the results of a proteome-wide analysis of RIP3-regulated phosphorylation sites using cells from wildtype (RIP3 +/+) and RIP3 knockout (RIP3-/-) mice. Because the activation of RIP3 requires stimulation by certain extracellular stimuli such as ligands of death receptors or Toll-like receptors, we compared the phosphorylation sites of lipopolysaccharide (LPS)-treated peritoneal macrophages from RIP3+/+and RIP3-/- mice and the phosphorylation sites of tumor necrosis factor (TNF)-treated RIP3+/+ and RIP3 -/- mouse embryonic fibroblast (MEF) cells. Stable isotope labeling by amino acids in cell culture and spike-in stable isotope labeling by amino acids in cell culture were used in the analyses of the MEFs and macrophages, respectively. Proteomic analyses using stable isotope labeling by amino acids in cell culture coupled with immobilized metal affinity chromatography-hydrophilic interaction liquid chromatography fractionation and nanoLC MS/MS identified 14,057 phosphopeptides in 4306 proteins from the macrophages and 4732 phosphopeptides in 1785 proteins from the MEFs. Analysis of amino acid sequence motifs among the phosphopeptides identified a potential motif of RIP3 phosphorylation. Among the phosphopeptides identified, 73 were found exclusively in RIP3+/+macrophages, 121 were detected exclusively from RIP3 +/+ MEFs, 286 phosphopeptides were induced more in RIP3+/+ macrophages than in RIP3-/- macrophages and 26 phosphopeptides had higher induction in RIP3+/+MEFs than in RIP3-/- cells. Many of the RIP3 regulated phosphoproteins from the macrophages and MEF cells are functionally associated with the cell cycle; the rest, however, appear to have diverse functions in that a number of metabolism related proteins were phosphorylated in macrophages and development related phosphoproteins were induced in MEFs. The results of our phosphoproteomic analysis suggest that RIP3 might function beyond necrosis and that cell type specific function of RIP3 exists. © 2012 by The American Society for Biochemistry and Molecular Biology, Inc.

Hong C.,CAS Institute of Vertebrate Paleontology and Paleoanthropology | Hong C.,Graduate University | Jiang H.,CAS Institute of Vertebrate Paleontology and Paleoanthropology | Jiang H.,Graduate University | And 8 more authors.
PLoS ONE | Year: 2012

Background: Proteomic approaches based on mass spectrometry have been recently used in archaeological and art researches, generating promising results for protein identification. Little information is known about eastward spread and eastern limits of prehistoric milking in eastern Eurasia. Methodology/Principal Finding: In this paper, an ancient visible food remain from Subeixi Cemeteries (cal. 500 to 300 years BC) of the Turpan Basin in Xinjiang, China, preliminarily determined containing 0.432 mg/kg cattle casein with ELISA, was analyzed by using an improved method based on liquid chromatography (LC) coupled with MALDI-TOF/TOF-MS to further identify protein origin. The specific sequence of bovine casein and the homology sequence of goat/sheep casein were identified. Conclusions/Significance: The existence of milk component in ancient food implies goat/sheep and cattle milking in ancient Subeixi region, the furthest eastern location of prehistoric milking in the Old World up to date. It is envisioned that this work provides a new approach for ancient residue analysis and other archaeometry field. © 2012 Hong et al.

Zhao Y.,Beijing Institute of Radiation Medicine | Jia W.,Beijing Institute of Radiation Medicine | Sun W.,Beijing Institute of Radiation Medicine | Jin W.,Asia Pacific Application Support Center | And 8 more authors.
Journal of Proteome Research | Year: 2010

Stable isotope dilution-multiple reaction monitoring-mass spectrometry (SID-MRM-MS), which is an alternative to immunoassay methods such as ELISA and Western blotting, has been used to alleviate the bottlenecks of high-throughput verification of biomarker candidates recently. However, the inconvenience and high isotope consumption required to obtain stably labeled peptide impedes the broad application of this method. In our study, the 18O-labeling method was introduced to generate stable isotope-labeled peptides instead of the Fmoc chemical synthesis and Qconcat recombinant protein synthesis methods. To make 18O-labeling suitable for absolute quantification, we have added the following procedures: (1) RapiGest SF and microwave heating were added to increase the labeling efficiency; (2) trypsin was deactivated completely by chemical modification using tris(2-carboxyethyl)phosphine (TCEP) and iodoacetamide (IAA) to prevent back-exchange of 18O to 16O, and (3) MRM parameters were optimized to maximize specificity and better distinguish between 18O-labeled and unlabeled peptides. As a result, the 18O-labeled peptides can be prepared in less than 1 h with satisfactory efficiency (>97%) and remained stable for 1 week, compared to traditional protocols that require 5 h for labeling with poor stability. Excellent separation of 18O-labeled and unlabeled peptides was achieved by the MRM-MS spectrum. Finally, through the combined improvement in 18O-labeling with multiple reaction monitoring, an absolute quantification strategy was developed to quantitatively verify hepatocellular carcinoma-related biomarker candidates, namely, vitronectin and clusterin, in undepleted serum samples. Sample preparation and capillary-HPLC analysis were optimized for high-throughput applications. The reliability of this strategy was further evaluated by method validation, with accuracy (%RE) and precision (%RSD) of less than 20% and good linearity (r2 > 0.99), and clinical validation, which were consistent with previously reported results. In summary, our strategy can promote broader application of SID-MRM-MS for biomarkers from discovery to verification regarding the significant advantages of the convenient and flexible generation of internal standards, the reduction in the sample labeling steps, and the simple transition. © 2010 American Chemical Society.

PubMed | CAS Wuhan Botanical Garden, Asia Pacific Application Support Center and Pusan National University
Type: Journal Article | Journal: Proteomics | Year: 2016

Seed germination is an important aspect of the plant life cycle, during which, reactive oxygen species (ROS) accumulate. The accumulation of ROS results in an increase in protein oxidation of which carbonylation is the most canonical one. However, there is insufficient information concerning protein oxidation, especially carbonylation and its contribution to seed germination. In this study, biotin hydrazide labeled chromatography combined with sequential window acquisition of all theoretical fragment ion spectra (SWATH) method was used to analyze the dynamic pattern of protein carbonylation in rice embryos during germination. A total of 1872 unique proteins were quantified, among which 288 carbonylated peptides corresponding to 144 proteins were determined based on the filtering through mass shifts of modified amino acids. In addition, 66 carbonylated proteins were further analyzed based on their carbonylation intensity in four stages of germination. These identified carbonylated proteins were mainly involved in maintaining the levels of ROS, abscisic acid and seed reserves. Remarkably, a peroxiredoxin was found with 23 unique carbonylated peptides, and the expression of which was consistent with its increased activity. This study describes the dynamic pattern of carbonylated proteins during seed germination, and may help to further understand the biochemical mechanisms on this process.

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